The typical form of treatment for a number of medical conditions such as diabetes, iron deficiency anemia and cancer includes oral and intravenous drug delivery. However, both oral and intravenous forms of drug delivery treatment for these and other conditions have a number of limitations. In many cases, oral delivery can have poor absorption particularly in the presence of other medications as well as a number of side effects. Intravenous limitations include the requirement to mix and store the medication in liquid form as well as the use of sterile techniques in administration. These can be particularly problematic in third world countries where adequate refrigeration and sterile needles are not readily available, limiting shelf life and exposing the patient to infection. Also, IV administration can include several risk factors including anaphylaxis and cardiovascular complications. Thus, there is a need for improved methods of drug delivery for many forms of treatment.
Transdermal iontophoresis is a non-invasive method of propelling high concentrations of drug or other therapeutic agents through the skin by repulsive electromotive force using a small electrical charge. In order to facilitate ease of use to the patient, iontophoretic transdermal devices are portable and thus include a portable power source such as a battery so that the device can be worn or carried by the patient. Further, in some instances it is desirable for such power sources to be able to provide power for a period of hours each day possibly over multiple days in order to allow the patient to receive a selected drug during this period. Thus battery life can be a factor in the usability of a transdermal iontophoretic delivery device for the patient so that patient need not change batteries over the course of a single treatment or even over many treatments. Thus there is a need for approaches for improving battery life for transdermal iontophoretic delivery devices and systems.